20 thoughts on “Briggs & Stratton 17.5hp OHV Smoking

  1. oil breather on side of block stuck letting it suck oil into the carb….or it could be something totally different…lol Good luck! …

  2. Definitely a head gasket, they blow right between the cylinder and the chamber where the push rods are, very very common on these motors! They should have put a another bolt there to prevent it from happening!

  3. Son what you have there is a blown head gasket.Pull the head off and inspect the gasket because it will be blown between the cylinder and the push rod galley.Take down all the model numbers off the engine and go get yourself a new head gasket.New gasket and set the valves you will be good to go.

  4. Mine did the same thing, Troy bilt but same motor. I drained the oil and it had gas blowing all in it, filled the motor up with gas and oil. The breather hose was rotten so I changed it, and rebuilt the carb since I was told the float might be stuck. Got it cleared all up, went to mowing and blew it up. Oil and gas again except it came from the bottom of the motor. These lawn mowers now days aint nothing but junk. Had to finish with my 20 year old Murray, with the deck falling off.

  5. Blown head gasket between the pushrod galley and the cylinder. happens all the time on these Inteks. Whatever you do, always check your oil. If its higher than normal, clean the carb immediately. These engines are notorious for throwing rods.

  6. my friends says it blew a ring and something wrong with the valves.  I've always keep good oil in it.  Ran it for 9 years.  I put a new motor on it and been running good.. put a 20hp Intek on it.

  7. you have a blown head gasket, my MTD briggs engine that has well over 5100+ hours of runtime on it and still runs but has used a lot of oil….it has a blown head gasket that spits oil thru the breather tube into the intake of the carb, it does that too when it's full of oil and running at idle

  8. Check the compression with a compression tester first as this looks like an Intek engine I had to replace a cylinder head on (dropped valve pierced the cylinder head), the head gasket can blow near the pushrod valley thus causing the engine to suck oil into the combustion chamber from the crankcase.
    If there's very Little increase in compression on the compression test even with oil added in through the combustion chamber then you most likely have a blown head gasket,after removing the cylinder head, if there is no evidence of a blown head gasket then check further for broken piston rings and / or a damaged cylinder and / or piston (broken ring land).

  9. Mine did the same thing and it was a simple fix, I had over filled the oil because I wasn't on level ground when I checked it. Got it started again and moved to level ground, drained out some oil so full level was correct, still running good 2 years later

  10. Probably blown head gasket. Also possible that the engine (PCV positive crankshaft ventilation) breather went bad. Probably on this engine it is referred to as a reed breather. Cost about $7. Follow the rubber hose from your carb to the engine to find its location. Likely you have to pull the flywheel as it will be located partially under it. You take off two little screws for the cover and it is a thin plastic looking tab held down over a hole by a little screw. It releases oil pressure in the form of fumes that is circulated back into the engine some that escapes being burned in the carb. When it loses its flexibility it allows too much oil to be forced from your engine that ends up in the carb causing engine smoke and if bad enough will kill engine. First take off the rubber reed breather hose at the carb and crank up engine. If oil comes out the rubber hose or there is a lot of oil in the air breather or carb that is your problem. If not it could be rings, or valve problem, but more likely a head gasket that forces oil into your exhaust. On a nine year old mower used only for residential use, it is possible you have a bad valve seat due to excessive heat but unlikely and highly unlikely that you have bad rings. The rings and cylinder walls will last for decades if oil is changed regularly.

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